Without Koji Uehara’s nearly lights-out performance last season as the Red Sox’s fourth closer, the team’s championship might not have happened.

Still, Uehara insists his life is the same as it was a year ago.

“Nothing has changed at all,” he said through a translator.

If the same can be said about his performance this season, the Red Sox will be very happy.

Uehara joined the Red Sox last season as a free agent and was expected to be a part of the back end of the bullpen. But, he took over the closer’s role after injuries to Joel Hanrahan and Andrew Bailey. Junichi Tazawa took a shot at closing but was ineffective.

Manager John Farrell made Uehara his closer on June 21, and from that point on the right-hander was nearly unhittable: He appeared in 41 games, saving 20 games in 22 opportunities. Uehara gave up three runs — two earned — on 14 hits, one home run, two walks and 59 strikeouts for 0.41 ERA and held opponents to an .097 average.

Overall, in 73 appearances, he went 4-1 with a 1.09 ERA and 21 saves. He set a club record with 37 consecutive batters retired from Aug. 17 to Sept. 13.

Can Uehara, who will turn 39 on April 3, repeat what he did last season? Is it even fair to ask?

“Totally fair,” manager John Farrell said.

Uehara is entering his sixth season in the major leagues after a 10-season career in Japan. In five MLB seasons with the Orioles, Rangers, and Red Sox, he is 9-10 with a 2.42 ERA, 35 saves in 230 games (all but 12 in relief).

“Granted, his performance last year was outstanding,” Farrell said. “The line that he put up, the time of the year, the game, the importance. ... I keep going back to the years previous. This has been a very successful pitcher every year he’s been here in the States.”

Uehara is not concerned with his past success or production.

“It’s all in the past,” he said. “It’s not productive, so I didn’t really reflect on it.

“I don’t care about what people think,” Uehara added. “Every year is a challenge. I try to make that motivation to be better.”

But Uehara pitched an MLB career-high 88 innings, 51 more innings than with the Rangers in 2012, when a lat strain limited him to just 37 appearances.

The Red Sox will monitor his workload in spring training and into the season, but the right-hander won’t be limited because of it.

“The one thing that Koji was very clear on was that he felt he had some arm issues because of lack of use and then was used a little bit more frequently,” Farrell said. “And he felt the more consistent that he got to the mound and pitched in games it was better for his arm and he proved that to be the case.”

Uehara said he doesn’t feel any different this spring. Even though Farrell has said the closer’s job is his, he feels he still has to prove himself.

“I feel that I still have to earn it,” Uehara said. “I’m just preparing accordingly to win that position.”